Abstract: A first feedback loop to a regulator transistor within the drain circuit of the input field effect transistor (FET) serves to maintain the voltage across the drain-gate junction of the input FET at a constant value consistent with FET operation as a source follower, thereby mitigating junction to junction capacitances within the FET. A second feedback loop created guard circuits on the cases of the input FET and the drain circuit regulator transistor, thereby mitigating junction to external circuitry capacitances. A third feedback loop modifies essentially constant current flow in the source circuit of the input FET in order to compensate for capacitance within that circuit. When utilized in compact form for microprobing of low voltage nanosecond rise time signals, the amplifier demonstrates an effective input capacitance of less than 0.5 picofarads.

Abstract: A method of and an apparatus for magneto-resistively detecting information in a cross-tie memory system is disclosed. The detector includes a first conductive element, which is the terminating portion of an electrically-conducting wide-narrow edged propagating drive line, and second and third conductive elements that are serially aligned along a magnetic, serrated-edged data track, which three conductive elements form two gaps therebetween. The two gaps are oriented along the data track at respective narrow portions, a first narrow portion which may support a cross-tie but which second narrow portion will not support a cross-tie. A differential sense amplifier is coupled across the two gaps using the second narrow portion as a reference segment to differentially detect the presence vel non of a cross-tie in the first narrow portion.

Abstract: A constant current sink for a cathode ray tube (CRT) display system is disclosed. The display system includes X and Y deflection coil current drive systems including parallel coupled constant current sinks that establish the deflection-determining current levels that flow through the X and Y deflection coils. Each constant current sink draws a fixed current level, and one or more are selectively switched ON, i.e., caused to draw a fixed current level through the deflection coil load from a first power supply, or OFF, i.e., caused to draw the fixed current level from a second power supply, to establish the desired electron beam position on the CRT. Means are provided for correcting for the pin-cushion, i.e., non-linear, effects associated with a flat CRT face.